The present invention relates to edible diffusion-retarding fat-based films for food products.
In many food products, and in particular composite food products, such as coated, layered or filled products fat- and moisture-migration or diffusion upon storage from one food material to an adjacent food material causes product degradation due to the deleterious effects by the migrating material or component upon the appearance, the consistency, the microbiological or chemical stability and/or the flavour balance of the intruded or intruding material.
Accordingly, migration and diffusion effects provide a principal difficulty in terms of structural and compositional freedom and consumer acceptability. Food products suffering from degradation due to such migration or diffusion phenomena may be found in every food industry area where products are encountered requiring long-term physical separation of food materials from each other or environment.
Examples of diffusion-sensitive food products are encountered e.g. in the bakery industries, such as with baking mixes comprising fresh nut or fruit pieces, meat-filled pastries, pizzas, snack products and toasts, and in the confectionery, chocolate and dairy industries such as filled chocolates, in particular pralines, coated or wavered ice-creams, liquid-filled candy bars, cream-filled biscuits and the like.
In general the greater the difference in the fat or moisture content or in the type of fat between the adjacent food materials, the greater the risk of fat- or moisture-migration upon storage will be.
In the art the above problems of migration or diffusion into or between food materials have been approached by modification or adjustment of the food materials themselves, or by applying to or in-between adjacent food materials a film of an edible material more resistent to migration or diffusion, thereby slowing down deterioration of the food product upon storage.
In the area of bakery and confectionery products the use of triglyceride fats as, in particular, moisture barriers is known. Although dependent upon the storage temperatures involved generally barrier fats have a relatively high solids content at the storage temperature of the product, and comprise sufficient hardstock fat to provide a firm structure of the layer. Often in the application of such barrier fats a not always fully satisfactory compromise must be found between barrier efficiency on the one hand and layer thickness (or number of layers) and taste aspects on the other hand. An additional problem frequently encountered with particularly low-temperature applications of fat-based barrier layers is that of cracking of the barrier layer upon storage resulting in decreased barrier efficiency. Prior art hitherto has not provided a fully adequate solution.